Panelboard cabinet door latch



y 31, 1956 H. M. STHEGLITZ PANELBOARD CABINET DOOR LATCH Filed Feb. 14, 1952 FIGZ.

WM F f 0 EL "L w United States Patent Ofiice 2,757,032 Patented July 31, 1956 PANELBOARD CABINET noon LATCH Henry M. Stieglitz, St. Louis, Mo., assignor to Frank Adam Electric Company, St. Louis, Mo., a corporation of Missouri Application February 14, 1952, Serial No. 271,497

6 Claims. (Cl. 29234) This invention relates generally to panelboard and switchboard cabinets, and particularly to the lock for the doors thereof and other comparable lockers.

In the construction of panelboard cabinets, it has been heretofore customary to provide the doors with a latch, and also with shoot bolts engaging the frame of the cabinet at the extremities of the door. The shoot bolts are conventionally disposed on the interior of the door and maniplated by the same exterior handle which operates the latch. In order to accomplish the concomitant operation of all parts, the mechanisms heretofore provided have been bulky and projected inwardly to an extent such as to necessitate an increase in depth of the cabinet in order to assure adequate clearance from the electrical apparatus therein contained.

Such shoot bolts are mounted for movement in suitable guides permanently afiixed to the interior of the door, and in view of the nature of the mechanism with part on the outside and part on the inside of the door, it has heretofore been the practice to assemble the entire mechanism and afiix the guides to the door prior to painting the door. Only in this way, it has been thought, an unmarred painted surface could be presented in the finished product. Such practice of painting after the assembly of the shoot bolts has frequently necessitated the tedious operation of removing paint from adjacent, relatively movable parts where the film of paint might foul or otherwise hinder their easy operation.

The object of the present invention, generally stated, is to provide a panelboard door having a latch and shoot bolt operating mechanism which is of inconsiderable thickness.

A further object of the invention is to provide a door lock for doors of the character aforesaid, which is externally tamper-proof yet easy to assemble without marring the previously painted surface of the door.

The present invention contemplates that the operating mechanism on the interior of the door be plate-like. and preferably no thicker than the usual bolt lock, that the shoot bolt guides, and bolt lock be applied to the door.

before it is painted, and that the shoot bolts, latch, and operating handle be applied afterwards. This is achieved by providing a shoot bolt and guide arrangement, and operating mechanism of a character such that they may be assembled with each other and with the door after the guides are permanently aflixed thereto.

The invention further contemplates that the mechanism be constructed and arranged so that it may be locked from the exterior and so that no screw-threaded or releasable parts, accessible from the exterior, be manipulable to release the latch when locked.

Other objects and advantages will become apparent to those skilled in the art when the following description is read in connection with the accompanying drawings showing one illustrative embodiment of the invention and in which:

Figure 1 is a view in side elevation taken from'the interior of a panelboard cabinet and showing one embodiment of the shoot bolt and latch mechanism of the present invention applied to the door of that cabinet;

Figure 2 is a view in edge elevation of the door and showing one of the shoot bolts in position with other of the shoot bolts in the process of being applied;

Figure 3 is a sectional view taken along line 33 of Figure 1;

Figure 4 is an exploded view of the handle, latch, shoot bolt operating mechanism, and interconnecting parts;

Figure 5 is a sectional view taken along line 55 of Figure 1; and

Figure 6 is a sectional view taken along line 66 of Figure 1.

Referring now to the drawings for an illustrative embodiment of the invention, the conventional panelboard cabinet is provided with a frame, rabbet or flange 1 extending about the door opening. A door 2, which may be, and usually is, formed of sheet metal of dimensions slightly less than the exterior dimensions of frame 1, is mounted upon the frame by hinges 3 in the usual manner.

On the interior of door 2 a set of guides 4 and 5 for each shoot bolt is provided. The guide 4, near the extremity of the door, is formed of a continuous strip of sheet metal having. a central elevated portion and depressed end portions, which latter may be secured to the interior face of door 2, as by welding. The elevated central portion of guide 4 is proportioned so as to accommodate the cross-section of the shoot bolt and guide same in a rectilinear movement with a minimum of play. The guide 5, near the center of the door, is composed of two parts which are mounted upon the door and arranged in a manner corresponding to that above described in connection with the guide 4, but with a central separation 6 for a purpose to be later described. In cases where, as in the embodiment shown, there are a plurality of shoot bolts, a set of guides 4 and 5 is provided for each shoot bolt.

The shoot bolts 7 are in the form of elongated strips of metal which, in the main, are straight and flat, but whose outer extremities are curved, as shown at 8, so that, when in operative position within the guides 4 and 5, the curved tip 8 bends away from the plane of door 2 and the curved portion is adapted to be moved inwardly and outwardly across the inner edge of frame 1. At the opposite ends of shoot bolt 7, a pin 9 is provided so as to project inwardly therefrom. In assembling the shoot bolts with the door 2, the curved tip 8 is first inserted in guide 4, as shown in full lines in the lower half of Figure 2. Slight downward movement of the shoot bolt causes the remote end thereof to approach guide 5 as the curved portion of tip 8 passes through guide 4. Thereafter the shoot bolt 7 is moved further downwardly through guide 4 to a position considerably beyond the outward extreme operating position indicated by dotted lines in Figure 2 where the end of shoot bolt 7 (which is provided with pin 9) is disposed flat against the inside face of door 2 and beyond guide 5. When in the latter position, the shoot bolt may be moved rectilinearly toward guide 5, with pin 9 positioned to pass through separation 6 and therebeyond into engagement with the shoot bolt operating mechanism now to be described.

The shoot bolt operating mechanism comprises a platelike latch actuating member '11 in the form of a cam.

plate having an eccentric cam slot proportioned to receive pin 9 on each shoot bolt to be operated thereby. The

plate 11 may be provided with a lug 13 arranged to everlap the inner edge of frame 1 thereadjacent when the shoot bolts 7 overlap the edge of the frame and thereby constitute a latch. In the embodiment shown, .plate 11 is also provided with a recess 14 adapted to receive the bolt 15 of a conventional lock 16. The plate 11 is provided with a central polygonal hole 17 proportioned to interfit with a polygonally shaped portion of the shank of a stud 18. The stud 18 extends through a round hole 19 indoor 2 and on the exterior thereof engages handle 21. In the embodiment shown, the handle 21 is provided with a polygonal shaped hole corresponding in contour to the polygonal shape of stud 18 and the outer extremity of the stud is peened over the exterior handle 21, but it will be understood that the stud may be welded or otherwise secured to handle 21. Between handle 21 and the outer face of door 2, one or more washers 22 may be mounted on stud 18, but at the increment which passe through hole 19, a bearing Washer provided with a polygonal hole snugly interfitting with the polygonal shank of stud 18 is provided. The exterior contour of washer 23 is circular and concentric with stud 18 so that the edge of washer 23 constitutes a bearing surface supporting the assembly within hole 19. Between washer 23 and plate 11, another washer 24 may be provided. On the inside of plate 11, a lock washer 25, having a polygonal hole corresponding in shape and dimensions to the polygonal portion of stud 18, is mounted. Interengagement between the polygonally shaped portion of stud 18 and the parts above mentioned as having polygonal holes is such as to prevent relative rotational movement of those parts. The lock washer 25 is provided with a tab 26 which, at the time of assembly, is co-planar with the body of the washer, as shown in dotted lines in Figure 4. The inner extremity of stud 18 is screw-threaded to receive a nut 27. The threaded portion of stud 18 may be round or polygonal, as desired, so long as the contour is such as to provide a substantial extent of threaded surface. When the nut 27 is drawn up taut on the parts, tab 26 of lock washer 25 may be turned up against one of the polygonal surfaces of nut 27 so as to prevent loosening of the nut 27 on the stem 18. Preferably, the axial thickness of washer 23 is a few thousandths of an inch greater than the thickness of the metal of which the door is made, thereby to assure that the nut 27 cannot be drawn up too tight as to clamp the washers 22 and 24 against opposite faces of the door and thereby interfere with the ease of operation.

In assembling the several parts together, stud 18 is first secured to handle 21 and washers 22 next placed thereon. Washer 23 may then be applied or, if desired, the application delayed until after the sub-assembly just described has been positioned on the exterior of the door 2 with the threaded end of stud 18 projecting through hole 19. If washer 23 is not applied before the stud is passed through the door, it is applied immediately afterward. Then washer 24 may be applied, followed by plate 11. At the time of application of plate 11, care is taken to set the respective shoot bolt pins 9 in their corresponding cam slots 12. With the parts thus engaged, the lock washer 25 and nut 27 are placed in position. Finally, when the nut is drawn up, tab 26 is turned to the locking position. The arrangement is therefore such as to assure no binding between the door panel and the movable parts, and to assure no relative movement between the parts which are mounted upon the polygonal shank of stud 18, while at the same time maintaining the pins 9 seated in their respective cam slots 12 and preventing displacement of shoot bolts 7.

The operation of the mechanism is obvious. When the handle 21 is turned in one direction, the shoot bolts 7 are moved outwardly, and when it is turned in the opposite direction, they are moved inwardly. The outward move ment of the shoot bolts, of course, is simultaneous with the outward movement of lug 13 so that the extremities of the shoot bolts engage over the edge of frame 1 at the same time that lug 13 engages over the edge of frame 1.

With a mechanism of the kind described, it is possible to weld or otherwise permanently afiix the guides 4 and to the door prior to the painting operation. The door with its connected guides may be painted in any desired manner, as by dipping or spraying, and thereafter, when the paint is dry, the shoot bolts and the operating mechanism may be applied and interconnected without substantial likelihood of marring the painted surface, or performing operations thereon which inherently would require repainting.

From the foregoing description, those skilled in the art should readily understand the advantages of the invention and realize it accomplishes its objectives. While one complete embodiment has been disclosed in detail, it is not to be understood that the invention is limited to that embodiment. On the contrary, it is realized that many modifications, adaptations, and variations will present themselves to those skilled in the art without departing from the spirit of this invention; and it is therefore to be distinctly understood that such are, although not specifically described herein, contemplated by and within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. A latching mechanism adapted to be mounted for use on a cabinet door having a hole, said latching mechanism comprising a handle, a polygonal shank projecting from the handle, a pair of separable washers carried by the shank and being of a diameter larger than the door hole so as to ride against the opposite faces of the door, a third washer carried by the shank between the first two washers and being approximately of the same thickness and diameter as the hole in the door, a latch-actuating member carried by the shank over said washers, said washers and latch-actuating member having polygonal holes cooperable with said shank, a nut threaded on said shank over the latch-actuating member, and means for locking the nut against rotation.

2. A latching mechanism adapted to be mounted for use on a cabinet door having a hole therein, said latching mechanism comprising a handle, a stud projecting from the handle, said stud having a shank of polygonal crosssection, a latch-actuating member mounted on the polygonal shank of said stud, said latch-actuating member having a polygonal hole cooperable with said shank, a lock Washer having a polygonal hole fitting on said shank over said latch-actuating member, and a nut threaded on said shank over the lock washer, said lock washer having an ear adapted to be turned up in engagement with the periphery of said nut.

3. The combination of claim 2, wherein the shank of the stud is adapted to extend through a circular hole in the door, the entire shank being of polygonal cross section, and a washer having a polygonal hole seated over said shank between the handle and said latch-actuating memher, said Washer being approximately of the same diameter and thickness as the hole in the door so as to provide a rotatable seat for the stud.

4. A latching mechanism adapted to be mounted for use on a cabinet door having a door hole therein, said latching mechanism comprising a shoot bolt adapted to lie flat against the door with its inner end located adjacent the door hole, a rotary shaft adapted to extend through said door hole, a pair of separable washers carried by said shaft adapted to ride against the opposite faces of the door, a third washer carried by the shaft between the other two washers and being approximately of the same thickness and diameter as the hole in the door, the inner end of said shoot bolt having a pin adapted to project away from the door, and a slotted bolt-actuating plate secured to said shaft with said pin received within said slot, said three washers, slotted plate and shaft being assembled for non-rotary movement relative to one another.

5. A latching mechanism adapted to be mounted for use on a cabinet door, said latching mechanism comprising a stud adapted to be rotatably mounted on the door, an elongate shoot bolt adapted to extend from adjacent said stud to an edge of the door, an inner-shootbolt guide adapted to be secured to the door adjacent the inner end of the shoot bolt, said shoot bolt having a pin projecting therefrom at its inner end, said inner shoot-bolt guide having a separation proportioned to pass said pin, and a slotted bolt-actuating plate secured on said stud over the inner end of said shoot bolt with the pin thereof engaged within the slot of said plate.

6. Apparatus as set forth in claim 5, further including an outer guide for the shoot bolt which guide is adapted to be secured to the door adjacent an edge thereof, and said outer end of the shoot bolt being curved in the direction in which the pin on the inner end thereof projects, thereby permitting installation and removal of the shoot bolt without disturbing the guides therefor.

References Cited in the file of this patent UNITED STATES PATENTS Taylor et a1 May 3, 1904 Hofimann July 12, 1927 Coffee June 17, 1930 Palmquist June 28, 1932 Rowe Aug. 23, 1932 Anderson Dec. 25, 1934 Kingdon Aug. 16, 1938 Birdsall et al June 22, 1943 Kerr Sept. 6, 1949 

